Design of Fast Earth-Return Trajectories from a Lunar Base

The Apollo Lunar Program utilized efficient, i.e., Earth-return, transearth trajectories which employed parking orbits in order to minimize energy requirements. The thesis concentrates on a different type of transearth trajectory. These are direct - ascent, hyperbolic trajectories which omit the parking orbits in order to achieve short flight times to and from a future lunar base. The object of the thesis is the development of a three-dimensional transearth trajectory model and associated computer program for exploring trade-offs between flight-time and energy, given various mission constraints. The program also targets the Moon with a hyperbolic trajectory, which can with a time reversed trajectory; be used for targeting Earth impact points. The first-order model is based on an Earth-centered conic and a massless spherical Moon, using MathCAD version 3.0. This model is intended as the basis for future patched-conic formulation for the design of fast Earth-return trajectories. Applications include placing nuclear deterrent arsenals on the Moon, various space support related activities and finally protection against Earth-threatening asteroids and comets using lunar bases.